Hitherto, an apparatus of this type is adapted to predict a collision with an object of collision and detect the collision as disclosed in Japanese Unexamined Patent Application Publication No. 6-286581. A seatbelt is wound at a first winding load when the collision is predicted. The seatbelt is wound at a second winding load which is larger than the first winding load when the collision is detected,
As the apparatus in the related art as described above, although a passenger is protected by winding of seatbelt when a collision is predicted and when the collision is occurred, such winding of the seatbelt constrains the passenger, and if the constraining force of the seatbelt is too large, it gives the passenger a sense of discomfort. Therefore, it is desired to provide a winding mode and a winding load of the seatbelt which can protect a passenger while giving the passenger the sense of discomfort as little as possible.